Liquid cooling system and battery pack

Abstract

The present application provides a liquid cooling system and a battery pack. The liquid cooling system comprises at least one liquid cooling assembly; the liquid cooling assembly comprises a liquid cooling plate and a plastic current collecting member; the liquid cooling plate is arranged on a side surface of a battery cell group, is configured to be hollow, has a liquid cooling flow channel formed therein, and is provided with a liquid inlet leading to one end of the liquid cooling flow channel and a liquid outlet leading to the other end of the liquid cooling flow channel; the plastic current collecting member is injection-molded on the liquid cooling plate, is integrally arranged with the liquid cooling plate, and comprises a liquid inlet flow channel and a liquid outlet flow channel.

Description

Liquid cooling system and battery pack

[0001] This application claims priority to Chinese Patent Application No. 2024118976360, filed on December 20, 2024, entitled "Liquid Cooling System and Battery Pack", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery pack technology, specifically to a liquid cooling system and a battery pack. Background Technology

[0003] Currently, cylindrical battery cells are widely used in electric vehicles due to their higher energy density, better safety and stability, and lower cost, and are expected to become the future development trend of electric vehicle batteries. Large cylindrical battery packs require liquid cooling plates to contact the sides of the cells for thermal management. Taking a serpentine tube as an example, the serpentine tube liquid cooling plate has a large contact area with the cell, resulting in high cooling efficiency. At the same time, the parallel liquid cooling system of the serpentine tube has a small voltage drop, which helps to ensure the stable operation of the system. Summary of the Invention

[0004] In a first aspect, embodiments of this application provide a liquid cooling system, including at least one liquid cooling component for liquid cooling a battery cell assembly. The liquid cooling component includes:

[0005] A liquid cooling plate is disposed on the side of the battery cell assembly. The liquid cooling plate is hollow and forms a liquid cooling channel within it. The liquid cooling plate has an inlet connecting to one end of the liquid cooling channel and an outlet connecting to the other end of the liquid cooling channel; and...

[0006] A plastic manifold is injection molded onto a liquid cooling plate and integrally formed with the liquid cooling plate. The plastic manifold includes an inlet channel and an outlet channel. The inlet channel is configured to connect the liquid inlet and the liquid inlet pipe of the liquid cooling plate, and the outlet channel is configured to connect the liquid outlet and the liquid outlet pipe of the liquid cooling plate.

[0007] Secondly, embodiments of this application provide a battery pack, comprising:

[0008] A liquid cooling system, comprising multiple liquid cooling components arranged side-by-side; and,

[0009] Multiple cell groups are arranged side by side, with each cell group located between two adjacent liquid cooling components.

[0010] The liquid cooling system is configured as the liquid cooling system of the first aspect of this application.

[0011] The beneficial effects of the embodiments of this application are as follows:

[0012] In the embodiments of this application, the liquid cooling component in the liquid cooling system is configured to liquid cool the side of the battery cell assembly. The liquid cooling component includes a liquid cooling plate and a plastic manifold. The liquid cooling plate is disposed on the side of the battery cell assembly and includes a liquid cooling channel. The metal liquid cooling plate has high thermal conductivity, thereby ensuring the liquid cooling effect of the liquid cooling plate on the side of the battery cell assembly. At the same time, the liquid cooling plate is provided with an inlet and an outlet communicating with the liquid cooling channel. The inlet and the inlet pipe, and the outlet and the outlet pipe are connected by a plastic manifold. That is, the coolant flows through the inlet pipe and the inlet channel, and... The coolant flows from the inlet to the liquid cooling channel, where it exchanges heat with the battery cells during its flow, thus achieving liquid cooling of the battery cells' sides. The coolant then flows through the liquid cooling channel and from the outlet to the outlet channel, forming a liquid cooling circuit and improving the liquid cooling effect. By injection molding the plastic manifold onto the liquid cooling plate and integrating it with the liquid cooling plate, not only can the weight of the plastic manifold be reduced, thereby reducing the overall weight of the liquid cooling system, but the cost of the plastic manifold can also be reduced. Furthermore, the connection strength and sealing between the plastic manifold and the inlet or outlet interface can be guaranteed.

[0013] However, in related technologies, the current collector at the end of the serpentine tube liquid cooling plate is usually made of metal, and the current collector and the serpentine tube liquid cooling plate are connected and sealed by metal welding, which makes the overall liquid cooling system heavy and expensive. Attached Figure Description

[0014] Figure 1 is a first perspective view of the liquid cooling system provided in an embodiment of this application;

[0015] Figure 2 is an exploded schematic diagram of the liquid cooling system in Figure 1;

[0016] Figure 3 is an enlarged schematic diagram of part A in Figure 2;

[0017] Figure 4 is a three-dimensional schematic diagram of the plastic manifold in Figure 1;

[0018] Figure 5 is a cross-sectional view of BB in Figure 4;

[0019] Figure 6 is a front view of the connection between the liquid cooling plate and the plastic manifold in Figure 1;

[0020] Figure 7 is a second perspective view of the liquid cooling system provided in an embodiment of this application;

[0021] Figure 8 is an exploded schematic diagram of the liquid cooling system in Figure 7;

[0022] Figure 9 is an enlarged schematic diagram of part C in Figure 8;

[0023] Figure 10 is a three-dimensional schematic diagram of the plastic manifold in Figure 8;

[0024] Figure 11 is a cross-sectional view of DD in Figure 10;

[0025] Figure 12 is an enlarged schematic diagram of part E in Figure 11;

[0026] Figure 13 is a front view of the connection between the liquid cooling plate and the plastic manifold in Figure 8;

[0027] Figure 14 is a perspective view of the battery pack provided in an embodiment of this application.

[0028] The names of the components corresponding to the corresponding reference numerals in the figure are:

[0029] 1000 Battery Pack; 100 Liquid Cooling System; 1 Liquid Cooling Component; 11 Liquid Cooling Plate; a Liquid Cooling Channel; b Liquid Inlet; c Liquid Outlet; d Side; e Channel; 111a First End; 111b Second End; 112 Plate Segment; 1121 Connecting Plate Segment; 1122 Liquid Cooling Plate Segment; 12 Plastic Manifold; 121 Liquid Inlet Channel; 122 Liquid Outlet Channel; 123 First Plate Segment; 124 Second Plate Segment; 125 Limiting Step; 13 Connecting Part; 14 Connecting Pipe; 141 Outer Wall; 142 Limiting Rib; 143 Limiting Protrusion; 15 Connecting Component; 200 Cell Assembly; 201 Side; 300 External Piping; F1 Length Direction. Embodiments of the present invention

[0030] In a first aspect, this application provides a liquid cooling system 100. Referring to Figures 1, 3, 7, and 14, the liquid cooling system 100 includes at least one liquid cooling component 1, configured to liquid cool a battery cell assembly 200. The liquid cooling component 1 includes a liquid cooling plate 11 and a plastic current collector 12. The liquid cooling plate 11 is disposed on the side 201 of the battery cell assembly 200, and is hollow, with a liquid cooling channel a formed therein. One end of the liquid cooling channel a is provided on the liquid cooling plate 11. The liquid inlet b and the liquid outlet c are connected to the other end of the liquid cooling channel a; the plastic manifold 12 is injection molded on the liquid cooling plate 11 and is integrally formed with the liquid cooling plate 11. The plastic manifold 12 includes a liquid inlet channel 121 and a liquid outlet channel 122. The liquid inlet channel 121 is configured to connect the liquid inlet b and the liquid inlet pipe 301 of the liquid cooling plate 11, and the liquid outlet channel 122 is configured to connect the liquid outlet c and the liquid outlet pipe 302 of the liquid cooling plate 11.

[0031] It is known that in related technologies, the current collector is machined from a metal part, and then the machined current collector is welded to the liquid cooling plate 11 to form the liquid cooling system 100. The metal current collector not only increases the overall weight of the liquid cooling system 100, but the machining and metal welding processes also increase the cost of the liquid cooling system 100.

[0032] In some embodiments of this application, the liquid cooling plate 11 includes a liquid cooling channel a. The liquid cooling plate 11 is disposed on the side 201 of the battery cell assembly 200. The liquid cooling plate 11, made of metal, has high thermal conductivity, thereby ensuring the liquid cooling effect of the liquid cooling plate 11 on the side 201 of the battery cell assembly 200.

[0033] Meanwhile, the liquid cooling plate 11 is provided with an inlet b and an outlet c that connect to the liquid cooling channel a. A plastic manifold 12 is provided to connect the inlet b and the inlet pipe 301, and the outlet c and the outlet pipe 302. That is, the coolant flows through the inlet pipe 301 and the inlet channel 121, and flows from the inlet b to the liquid cooling channel a. During the flow of the coolant, it exchanges heat with the battery cell assembly 200, thereby achieving liquid cooling of the side 201 of the battery cell assembly 200. The coolant flows through the liquid cooling channel a and flows from the outlet c to the outlet channel 122. This forms a liquid cooling circuit and improves the liquid cooling effect.

[0034] In some embodiments of this application, the plastic manifold 12 is injection molded onto the liquid cooling plate 11 and is integrally disposed with the liquid cooling plate 11. The injection-molded plastic manifold 12 is lighter than the metal manifold, thereby reducing the overall weight of the liquid cooling system 100. The direct injection molding of the plastic manifold 12 onto the liquid cooling plate 11 simplifies the manufacturing and assembly process of the plastic manifold 12 compared to machining and metal welding processes, resulting in lower costs and thus reducing the overall manufacturing cost of the liquid cooling system 100. Furthermore, the injection molding of the plastic manifold 12 integrally disposed with the liquid cooling plate 11 ensures the connection strength and sealing performance between the plastic manifold 12 and the liquid cooling plate 11.

[0035] The plastic manifold 12 is provided with an inlet port 126 and an outlet port 127. The inlet port 126 is connected to the inlet channel 121 and the inlet pipe 301; the outlet port 127 is connected to the outlet channel 122 and the outlet pipe 302.

[0036] This application does not impose specific limitations on the number and location of the plastic current collectors 12. In some embodiments, a single liquid cooling plate 11 cools two battery cell groups 200, with an inlet b and an outlet c respectively located at both ends of the liquid cooling plate 11, and a current collector is respectively located at the inlet b and outlet c. In another embodiment, a single liquid cooling plate 11 cools two battery cell groups 200, with an inlet b and an outlet c located on the same side of one end of the liquid cooling plate 11, and a current collector is located at one end of the liquid cooling plate 11. In some other embodiments, a single liquid cooling plate 11 is bent and can cool more than three battery cell groups 200 simultaneously, with an inlet b and an outlet c respectively located on both ends of the liquid cooling plate 11, and a current collector is respectively located at the inlet b and outlet c. No specific limitations are imposed here; the plastic current collectors of this application are applicable to various types of liquid cooling plates 11.

[0037] In the embodiment of "cooling two battery cell groups 200 with a single liquid cooling plate 11", the two ends of the liquid cooling channel a can be arranged on the same side or opposite to each other; correspondingly, the liquid inlet b and liquid outlet c on the liquid cooling plate 11 can be arranged on the same side or opposite to each other.

[0038] Taking "the two ends of the liquid cooling channel a being arranged on the same side" as an example, this application does not impose specific limitations on the structure of the liquid cooling channel a. In some embodiments, the liquid cooling channel a includes a first flow section, a second flow section, and a connecting flow section. The first flow section and the second flow section are arranged in parallel and along the length direction F1 of the cell assembly 200. On the length direction F1 of the cell assembly 200, the two ends of the first flow section and the second flow section on the same side are connected by the connecting flow section, and the other two ends of the first flow section and the second flow section on the same side respectively form the two ends of the liquid cooling channel a.

[0039] In other embodiments, the liquid cooling channel a includes a third flow section and a fourth flow section. The third flow section and the fourth flow section are arranged in parallel and along the length direction F1 of the cell assembly 200. On the length direction F1 of the cell assembly 200, the two ends of the third flow section and the fourth flow section on the same side penetrate the liquid cooling plate 11. The liquid cooling plate 11 is also provided with a connecting member 15 to connect the two ends of the third flow section and the fourth flow section on the same side. The other two ends of the third flow section and the fourth flow section on the same side respectively form the two ends of the liquid cooling channel a.

[0040] The following description uses the example of "liquid cooling channel a including a third flow section and a fourth flow section, with the two ends of the third and fourth flow sections on the same side penetrating the liquid cooling plate 11 and connected by a connecting member 15, and the other two ends of the third and fourth flow sections on the same side respectively forming the two ends of liquid cooling channel a". The two ends of liquid cooling channel a are arranged on the same side; a connecting part 13 is integrally formed on the liquid cooling plate 11, and the connecting part 13 is hollow, with one end connected to both ends of the liquid cooling channel a, and the other end forming an inlet b and an outlet c; a plastic manifold 12 is injection molded at the other end of the connecting part 13; thus, only one plastic manifold 12 needs to be set on each liquid cooling plate 11, which can minimize the number of plastic manifolds 12; at the same time, the plastic manifold 12 is injection molded on the connecting part 13, making it easier to injection mold the plastic manifold 12.

[0041] Please refer to Figures 2 and 3. In the length direction F1 of the cell assembly 200, the liquid cooling plate 11 has a first end 111a and a second end 111b opposite to each other. One end of the third flow section passes through the second end 111b, and one end of the fourth flow section on the same side passes through the second end 111b. A connecting member 15 is provided at the second end 111b to connect the third flow section and the fourth flow section.

[0042] Please refer to Figures 1 to 6. In some embodiments of this application, the two ends of the liquid cooling channel a are disposed near the first end 111a; the first end 111a is provided with a channel e connecting the two ends of the liquid cooling channel a, and the end of the channel e forms an inlet b and an outlet c; wherein, the connecting part 13 includes the first end 111a, and the plastic manifold 12 is injection molded on the first end 111a.

[0043] In some embodiments of this application, the two ends of the liquid cooling channel a are disposed close to the first end 111a. The first end 111a forms an inlet b and an outlet c that connect the liquid cooling channel a. The first end 111a forms a connecting part 13, and the plastic manifold 12 is directly injection molded onto the liquid cooling plate 11.

[0044] Specifically, in some embodiments, when the plastic current collector 12 is injection molded onto the first end 111a, one end of the plastic current collector 12 is sleeved on the outside of the first end 111a. Referring to Figure 6, along the length F1 of the cell assembly 200, wherein:

[0045] The insertion length between the first end 111a and the plastic manifold 12 is set to H1, and 2mm≤H1≤200mm. When the insertion length H1 between the plastic manifold 12 and the liquid cooling plate 11 is less than 2mm, the connection strength between the plastic manifold 12 and the liquid cooling plate 11 is low, and the plastic manifold 12 is very easy to fall off from the liquid cooling plate 11. When the insertion length H1 between the plastic manifold 12 and the liquid cooling plate 11 is greater than 200mm, the size of the plastic manifold 12 needs to be made larger, thereby increasing the overall size of the liquid cooling assembly 1. Setting the insertion length H1 between the first end 111a and the plastic manifold 12 to 2mm~200mm not only ensures that the overlap length between the plastic manifold 12 and the liquid cooling plate 11 is sufficient, thereby improving the connection strength between the plastic manifold 12 and the liquid cooling plate 11, but also eliminates the need to increase the size of the plastic manifold 12, thereby controlling the overall size of the liquid cooling assembly 1.

[0046] The insertion length between the first end 111a and the plastic manifold 12 is set to H1, and the length of the connecting part 13 is set to H2, where 1mm ≤ H2 - H1 ≤ 50mm. It is known that before injection molding the plastic manifold 12 onto the first end 111a, the outer wall 141 of the liquid cooling plate 11 near the first end 111a needs to undergo surface treatment to form the connecting part 13. After the first end 111a is inserted into the plastic manifold 12, a portion of the surface-treated area will be exposed outside the plastic manifold 12, with the exposed dimension set to 1mm~50mm. When the length difference is less than 1mm... At that time, due to the manufacturing tolerance of the plastic manifold 12, the area covered by the plastic manifold 12 on the liquid cooling plate 11 will exceed the area on the liquid cooling plate 11 that has undergone surface treatment, thereby reducing the connection strength between the plastic manifold 12 and the liquid cooling plate 11. When the length difference is greater than 50mm, the area on the liquid cooling plate 11 that has undergone surface treatment is large, which will increase the process cost. Setting the length exceeding the plastic manifold 12 to 1mm~50mm not only ensures that the plastic manifold 12 overlaps the area on the liquid cooling plate 11 that has undergone surface treatment, but also controls the range of the area on the liquid cooling plate 11 that has undergone surface treatment, thus avoiding process waste.

[0047] This application does not impose specific restrictions on the insertion length H1 between the connecting part 13 and the plastic current collector 12. The insertion length H1 between the connecting part 13 and the plastic current collector 12 can be set to 2mm, 10mm, 20mm, 50mm, 100mm and 200mm.

[0048] This application does not impose specific restrictions on the length difference H2-H1, which can be set to 1mm, 10mm, 20mm, 30mm, 40mm and 50mm.

[0049] Please refer to Figures 7 to 13. In some embodiments of this application, the two ends of the liquid cooling channel a are arranged on the same side and pass through the first end 111a; a connecting pipe 14 is fixedly connected to the first end 111a, one end of the connecting pipe 14 is connected to both ends of the liquid cooling channel a respectively, and the other end of the connecting pipe 14 forms an inlet b and an outlet c; wherein, the connecting part 13 includes the connecting pipe 14, and the plastic manifold 12 is injection molded on the other end of the connecting pipe 14.

[0050] In some embodiments of this application, a connecting pipe 14 is fixedly connected to the first end 111a, and the other end of the connecting pipe 14 forms an inlet b and an outlet c; the plastic manifold 12 is injection molded onto the other end of the connecting pipe 14. In actual manufacturing, the plastic manifold 12 can be injection molded onto the connecting pipe 14 first, and then the connecting pipe 14 can be welded to the liquid cooling plate 11, which can reduce the injection molding difficulty of the plastic manifold 12.

[0051] Specifically, in some embodiments, the plastic current collector 12 is sleeved on the outside of the connecting pipe 14, as shown in Figure 12, along the length direction F1 of the cell assembly 200, wherein:

[0052] The insertion length H3 between the connecting pipe 14 and the plastic manifold 12 is 2mm ≤ H3 ≤ 200mm. When the insertion length H3 between the plastic manifold 12 and the connecting pipe 14 is less than 2mm, the connection strength between the plastic manifold 12 and the connecting pipe 14 is low, and the plastic manifold 12 is very easy to detach from the connecting pipe 14. When the insertion length H3 between the plastic manifold 12 and the connecting pipe 14 is greater than 200mm, the size of the plastic manifold 12 needs to be made larger, thereby increasing the overall size of the liquid cooling assembly 1. Setting the insertion length H3 between the plastic manifold 12 and the connecting pipe 14 to 2mm~200mm not only ensures that the overlap length between the plastic manifold 12 and the connecting pipe 14 is sufficient, thereby improving the connection strength between the plastic manifold 12 and the connecting pipe 14, but also eliminates the need to increase the size of the plastic manifold 12, thereby controlling the overall size of the liquid cooling assembly 1.

[0053] The insertion length of the connecting pipe 14 and the plastic manifold 12 is set to H3, and the length of the connecting pipe 14 is set to H4, with 5mm ≤ H4 - H3 ≤ 200mm. When the length of the connecting pipe 14 exposed outside the plastic manifold 12, H4 - H3, is less than 5mm, the welding space between the connecting pipe 14 and the liquid cooling plate 11 is insufficient. When the length of the connecting pipe 14 exposed outside the plastic manifold 12, H4 - H3, is greater than 200mm, the size of the connecting pipe 14 needs to be made larger, thereby increasing the overall size of the liquid cooling assembly 1. Setting the length of the connecting pipe 14 exposed outside the plastic manifold 12, H4 - H3, to 5mm~200mm not only ensures that the connecting pipe 14 and the liquid cooling plate 11 have sufficient welding space, but also allows for reasonable control of the size of the connecting pipe 14.

[0054] The distance between the plastic manifold 12 and the first end 111a is set to H5, where H5 is greater than or equal to 3mm. It is known that one end of the connecting pipe 14 is sleeved on the first end 111a, and the plastic manifold 12 is injection molded on the other end of the connecting pipe 14. Typically, the connecting pipe 14 and the first end 111a are laser welded together. The distance H5 between the plastic manifold 12 and the first end 111a is set to be greater than or equal to 3mm, thereby ensuring that there is sufficient distance between the first end 111a and the plastic manifold 12, thus providing sufficient welding space for the connecting pipe 14.

[0055] This application does not impose specific restrictions on the insertion length H3 between the connecting pipe 14 and the plastic manifold 12. The insertion length H3 between the connecting pipe 14 and the plastic manifold 12 can be set to 2mm, 10mm, 20mm, 50mm, 100mm and 200mm.

[0056] This application does not impose specific restrictions on the length H4-H3 of the connecting pipe 14 exposed outside the plastic manifold 12. The length H4-H3 of the connecting pipe 14 exposed outside the plastic manifold 12 can be set to 5mm, 10mm, 20mm, 50mm, 100mm and 200mm.

[0057] This application does not impose specific restrictions on the distance H5 between the plastic manifold 12 and the first end 111a. The distance H5 between the plastic manifold 12 and the first end 111a is set to be greater than or equal to 3mm and less than or equal to H4-3mm. The distance H5 between the plastic manifold 12 and the first end 111a can be set to 3mm, 10mm, 20mm, 50mm, 100mm and 197mm.

[0058] In some embodiments, please refer to FIG9, the outer wall 141 of the connecting pipe 14 is provided with a limiting rib 142, and the plastic manifold 12 is sleeved on the outside of the connecting pipe 14 and abuts against the limiting rib 142; by setting the limiting rib 142, the insertion length H3 between the connecting pipe 14 and the plastic manifold 12 is limited, thereby preventing the plastic manifold 12 from exceeding the maximum insertion length during injection molding.

[0059] In some embodiments, a limiting protrusion 143 protrudes from the inner wall of the connecting pipe 14, and the first end 111a is inserted into one end of the connecting pipe 14 and abuts against the limiting protrusion 143. By setting the limiting protrusion 143, the insertion position of the connecting pipe 14 and the first end 111a is restricted, thereby preventing the first end 111a from being too close to the plastic manifold 12 due to the large insertion length with the connecting pipe 14, and thus ensuring that there is a sufficient distance between the first end 111a and the plastic manifold 12 to provide sufficient welding space for the connecting pipe 14.

[0060] Please refer to Figures 11 and 12. The plastic manifold 12 is provided with a stepped groove 123. In the direction away from the groove opening 123a of the stepped groove 123, the stepped groove 123 includes a first groove segment 1231 and a second groove segment 1232 with decreasing groove diameters. The connection between the first groove segment 1231 and the second groove segment 1232 forms a stepped surface 1233. The second groove segment 1232 has two independent cavities 1234, which respectively form an inlet flow channel 121 and an outlet flow channel 122. The connecting part 13 is inserted into the groove opening 123a of the stepped groove 123 and abuts against the stepped surface 1233. That is to say, the plastic manifold 12 has a first groove segment 1231 and a second groove segment 1232. The first groove segment 1231 forms the inlet flow channel 121 and the outlet flow channel 122. The second groove segment 1232 is sleeved on the outside of the connecting part 13, which can reduce the injection molding difficulty of the plastic manifold 12.

[0061] Specifically, a stepped surface 1233 is formed at the connection between the first groove segment 1231 and the second groove segment 1232. The connecting part 13 is inserted into the groove opening 123a of the stepped groove 123 and abuts against the stepped surface 1233. By setting the stepped groove 123 and the stepped surface 1233, the insertion length H3 between the connecting pipe 14 and the plastic manifold 12 is limited, thereby preventing the plastic manifold 12 from exceeding the maximum insertion length during injection molding.

[0062] Furthermore, in some embodiments, an annular groove 1235 is provided on the stepped surface 1233, and the width of the annular groove 1235 is less than the wall thickness of the connecting portion 13. The annular groove 1235 makes the interior of the plastic manifold 12 hollow, which can reduce the weight of the plastic manifold 12, thereby reducing the overall weight of the liquid cooling system 100.

[0063] It is known that the plastic manifold 12 is injection molded onto the first end 111a of the liquid cooling plate 11, or the plastic manifold 12 is injection molded onto the connecting pipe 14. In order to improve the connection strength of the plastic manifold 12, the liquid cooling plate 11 or the connecting pipe 14 needs to be surface treated. Typically, the metal surface is subjected to nano-sizing, plasma cleaning, oxidation treatment, passivation treatment, or anodizing, thereby improving the connection strength of the plastic manifold 12.

[0064] After surface treatment of the liquid cooling plate 11 or the connecting pipe 14, the other end of the connecting part 13 extends away from the liquid cooling plate 11, and the outer diameter of the connecting part 13 is gradually reduced in the direction away from the liquid cooling plate 11; the plastic manifold 12 is sleeved on the outside of the connecting part 13; in this way, the connection strength between the plastic manifold 12 and the connecting part 13 can be improved.

[0065] This application does not impose specific restrictions on the material of the plastic current collector 12. The material of the plastic current collector 12 can be one of PA66+GF (nylon 66 with glass fiber), PPS (polyphenylene sulfide), PPE (polyphthalamide), and PA12 (nylon 12). Using nylon as the material for the plastic current collector 12 not only reduces the risk of electrical short circuits and the cost of insulation coating, but also, due to its lower density, increases the overall energy density of the battery pack 1000.

[0066] In some embodiments, the side surface d of the liquid cooling plate 11 is at least partially attached to and shaped to the side surface 201 of the battery cell assembly 200; the side surface d of the liquid cooling plate 11 is attached to and shaped to the side surface 201 of the battery cell assembly 200. This increases the contact area between the liquid cooling plate 11 and the battery cell assembly 200, thereby increasing the cooling effect of the liquid cooling system 100.

[0067] It is known that the mainstream cell types on the market include cylindrical cells, prismatic cells, and pouch cells. Among them, 4680 cylindrical batteries have higher energy density, better safety and stability, and higher economic efficiency after assembly, and are expected to become the development trend of electric vehicle batteries.

[0068] Taking "the battery cells in the battery cell assembly 200 are cylindrical batteries" as an example, the liquid cooling plate 11 is set as a serpentine tube or a metal harmonica tube; in this way, the serpentine tube or the metal harmonica tube contacts the side 201 of the cylindrical battery cell for heat exchange. The contact area between the serpentine tube or the metal harmonica tube and the cylindrical battery cell is large, which makes the cooling efficiency of the serpentine tube or the metal harmonica tube high, and thus makes the pressure drop of the liquid cooling system 100 small.

[0069] This application does not impose specific limitations on the structure of the liquid cooling plate 11. Taking "the liquid cooling plate 11 is set as a serpentine tube" as an example, please refer to Figures 2 and 8. In the length direction F1 of the cell assembly 200, the liquid cooling plate 11 includes multiple plate segments 112 spliced ​​together. The multiple plate segments 112 include connecting plate segments 1121 located at both ends of the liquid cooling plate 11, and multiple liquid cooling plate segments 1122 located between two connecting plate segments 1121. The two connecting plate segments 1121 are set as straight plate segments 112. Each liquid cooling plate segment 1122 is attached to the side 201 of one cell in the cell assembly 200 and the shape is adapted to it. The liquid inlet b and the liquid outlet c are set on the same side and are set on one connecting plate segment 1121. The plastic current collector 12 is correspondingly injection molded on the connecting plate segment 1121.

[0070] In this embodiment, the liquid cooling plate segment 1122 is attached to the side 201 of one of the cells in the cell assembly 200 and the shape is adapted to each other, thereby ensuring that the liquid cooling plate segment 1122 and the cell have a large contact area, thereby improving the liquid cooling effect of the liquid cooling plate 11; at the same time, the connecting plate segment 1121 is set as a straight plate segment, so that the plastic current collector 12 is easier to be injection molded on the connecting plate segment 1121.

[0071] Typically, multiple battery cell groups 200 are provided. In order for multiple battery cell groups 200 to receive liquid cooling, in some embodiments, the liquid cooling system 100 includes multiple liquid cooling components 1, which are arranged side by side, with a battery cell group 200 placed between two adjacent liquid cooling components 1, so as to liquid cool both sides of the battery cell group 200 respectively. With this arrangement, both sides of each battery cell group 200 can be liquid cooled by the liquid cooling components 1, which not only makes the structural layout of the liquid cooling system 100 more reasonable, but also improves the liquid cooling effect of the liquid cooling system 100.

[0072] It is understood that this application does not restrict the connection method of multiple liquid cooling components 1; multiple liquid cooling components 1 can be set in parallel or in series; if multiple liquid cooling components 1 are set in parallel, the flow resistance of the liquid cooling system 100 can be reduced.

[0073] Secondly, embodiments of this application also provide a battery pack 1000. Referring to Figure 14, the battery pack 1000 includes a liquid cooling system 100 and multiple cell groups 200; the liquid cooling system 100 includes multiple liquid cooling components 1 arranged side-by-side; the multiple cell groups 200 are arranged side-by-side, with each cell group 200 located between two adjacent liquid cooling components 1. It should be noted that the liquid cooling system 100 is configured as the liquid cooling system 100 of the first aspect of this application, meaning that the liquid cooling system 100 possesses all the technical features of the liquid cooling system 100 of the first aspect of this application, i.e., the battery pack 1000 includes all embodiments of the liquid cooling system 100 of the first aspect of this application.

[0074] The liquid cooling assembly 1 includes a liquid cooling plate 11 and a plastic current collector 12. The liquid cooling plate 11 includes a liquid cooling channel a. The liquid cooling plate 11 is disposed on the side 201 of the battery cell assembly 200. The liquid cooling plate 11, made of metal, has high thermal conductivity, thereby ensuring the liquid cooling effect of the liquid cooling plate 11 on the side 201 of the battery cell assembly 200.

[0075] Meanwhile, the liquid cooling plate 11 is provided with an inlet b and an outlet c that connect to the liquid cooling channel a. A plastic manifold 12 is provided to connect the inlet b and the inlet pipe 301, and the outlet c and the outlet pipe 302. That is, the coolant flows through the inlet pipe 301 and the inlet channel 121, and flows from the inlet b to the liquid cooling channel a. During the flow of the coolant, it exchanges heat with the battery cell assembly 200, thereby achieving liquid cooling of the side 201 of the battery cell assembly 200. The coolant flows through the liquid cooling channel a and flows from the outlet c to the outlet channel 122. This forms a liquid cooling circuit and improves the liquid cooling effect.

[0076] The plastic manifold 12 is injection molded onto the liquid cooling plate 11 and is integrally formed with the liquid cooling plate 11. The injection-molded plastic manifold 12 is lighter than the metal manifold, thereby reducing the overall weight of the liquid cooling system 100. The direct injection molding of the plastic manifold 12 onto the liquid cooling plate 11 simplifies the manufacturing and assembly process of the plastic manifold 12 compared to machining and metal welding processes, resulting in lower costs and thus reducing the overall manufacturing cost of the liquid cooling system 100. Furthermore, the integral formation of the plastic manifold 12 with the liquid cooling plate 11 through injection molding ensures the connection strength and sealing performance between the plastic manifold 12 and the liquid cooling plate 11.

Claims

1. A liquid cooling system comprising at least one liquid cooling assembly configured to liquid cool a group of battery cells, the liquid cooling assembly comprising: a liquid cooling plate arranged on a side of the group of battery cells, the liquid cooling plate being hollow and having a liquid cooling flow channel formed therein, the liquid cooling plate having a liquid inlet opening and a liquid outlet opening formed therein and communicating with opposite ends of the liquid cooling flow channel; and a plastic current collector integrally formed with the liquid cooling plate, the plastic current collector comprising a liquid inlet flow channel and a liquid outlet flow channel, the liquid inlet flow channel being configured to communicate with the liquid inlet opening and a liquid inlet pipe, and the liquid outlet flow channel being configured to communicate with the liquid outlet opening and a liquid outlet pipe. The opposite ends of the liquid cooling flow channel are arranged on the same side. The liquid cooling plate integrally has a connecting portion formed therein, the connecting portion being hollow and having one end communicating with the opposite ends of the liquid cooling flow channel and the other end having the liquid inlet opening and the liquid outlet opening formed therein.

2. The liquid cooling system of claim 1, wherein, The plastic current collector is integrally formed with the other end of the connecting portion. In a length direction of the group of battery cells, the liquid cooling plate has a first end portion, and the opposite ends of the liquid cooling flow channel are arranged close to the first end portion. The first end portion has a passage formed therein and communicating with the opposite ends of the liquid cooling flow channel, and the passage has end portions forming the liquid inlet opening and the liquid outlet opening.

3. The liquid cooling system of claim 2, wherein, The connecting portion comprises the first end portion, and the plastic current collector is integrally formed with the first end portion. One end of the plastic current collector is arranged outside the first end portion in the length direction of the group of battery cells, and wherein: The first end portion and the plastic current collector have a joint length H1, and 2mm≤H1≤200mm; and / or 4. The liquid cooling system of claim 3, wherein, The first end portion and the plastic current collector have a joint length H1, and the connecting portion has a length H2, and 1mm≤H2-H1≤50mm. In the length direction of the group of battery cells, the liquid cooling plate has a first end portion, the opposite ends of the liquid cooling flow channel penetrate through the first end portion, and the first end portion is fixedly connected with a connecting pipe, one end of the connecting pipe communicates with the opposite ends of the liquid cooling flow channel, and the other end of the connecting pipe forms the liquid inlet opening and the liquid outlet opening. The connecting portion comprises the connecting pipe, and the plastic current collector is integrally formed with the other end of the connecting pipe.

5. The liquid cooling system of claim 2, wherein, The plastic current collector is arranged outside the connecting pipe in the length direction of the group of battery cells, and wherein: The connecting pipe and the plastic current collector have a joint length H3, and 2mm≤H3≤200mm; and / or 6. The liquid cooling system of claim 5, wherein, The connecting pipe and the plastic current collector have a joint length H3, the connecting pipe has a length H4, and 5mm≤H4-H3≤200mm; and / or A distance between the plastic current collector and the first end portion is H5, and H5 is greater than or equal to 3mm. The connecting pipe has a limiting protruding rib protruding from an outer wall thereof. The plastic current collector is arranged outside the connecting pipe and abuts against the limiting protruding rib.

7. The liquid cooling system of claim 5, wherein, The connecting pipe has a limiting protruding rib protruding from an inner wall thereof. ​ 8. The liquid cooling system of claim 5, wherein, ​ The first end is inserted into one end of the connecting pipe and abuts against the limiting protrusion.

9. The liquid cooling system of claim 2, wherein, The plastic current collector is provided with a stepped groove, in a direction away from a groove opening of the stepped groove, the stepped groove comprises a first groove section and a second groove section with decreasing groove diameters, a step surface is formed at a connection between the first groove section and the second groove section, and two independent cavities are formed in the second groove section to correspond to the liquid inlet flow channel and the liquid outlet flow channel respectively. The connecting part is inserted into the groove opening of the stepped groove and abuts against the step surface.

10. The liquid cooling system of claim 9, wherein, The step surface is provided with an annular groove, and a width of the annular groove is smaller than a wall thickness of the connecting part.

11. The liquid cooling system of claim 2, wherein, The other end of the connecting part extends away from the liquid cooling plate, and in a direction away from the liquid cooling plate, an outer diameter of the connecting part is tapered.

12. The liquid cooling system of any of claims 2-11, wherein, A side surface of the liquid cooling plate at least partially matches and is shaped to fit a side surface of the battery cell group.

13. The liquid cooling system of claim 12, wherein, The liquid cooling plate is provided as a serpentine pipe or a metal mouth organ pipe.

14. The liquid cooling system of claim 12, wherein, In a length direction of the battery cell group, the liquid cooling plate comprises a plurality of plate sections spliced with each other, the plurality of plate sections comprise two connecting plate sections at two ends of the liquid cooling plate and a plurality of liquid cooling plate sections between the two connecting plate sections, the two connecting plate sections are provided as straight plate sections, and each of the liquid cooling plate sections matches and is shaped to fit a side surface of one battery cell in the battery cell group. The liquid inlet and the liquid outlet are provided on one side and on one of the connecting plate sections, and the plastic current collector is injection molded on the connecting plate section.

15. The liquid cooling system of any of claims 2-11, wherein, The liquid cooling system comprises a plurality of the liquid cooling assemblies, the plurality of the liquid cooling assemblies are provided side by side, one battery cell group is provided between two adjacent liquid cooling assemblies to cool two sides of the battery cell group respectively.

16. The liquid cooling system of claim 1, wherein, The material of the plastic current collector can be one of nylon 66+glass fiber, polyphenylene sulfide, polyphthalamide, and nylon 12.

17. A battery pack comprising: a liquid cooling system comprising a plurality of liquid cooling assemblies, the plurality of liquid cooling assemblies being provided side by side; and, a plurality of battery cell groups, the plurality of battery cell groups being provided side by side, each of the battery cell groups being located between two adjacent liquid cooling assemblies; wherein the liquid cooling system is provided as the liquid cooling system according to any one of claims 1-16.

Images